What are the EMC risks associated with PCB ground plane segmentation in data center switches?

Ground plane partitioning on data center switch PCBs disrupts high-speed signal return paths, forcing return current to bypass and form loop antennas.

Risk quantification: With a 5mm ground plane partition width, signal lines crossing the partition experience a 18-22dB increase in common-mode radiation at 1GHz; a potential difference of 0.5V-1.2V between adjacent partitioned ground planes can lead to false logic triggering.

Design no-go zones: Ground plane partitioning is strictly prohibited below BGAs, in the projection area of high-speed differential lines, and in the connector pin area; if partitioning is unavoidable, a stitching capacitor (0.1μF + 0.001μF in parallel) should be added at the partition bridging point.

Ground plane partitioning is a primary inspection item in the EMC audit of Yinte Electronics, and its rectification is extremely difficult.